Brake beam paddle caps

ABSTRACT

A brake beam assembly for a railway car truck includes a brake beam configured to be mounted between opposed side frames of the railway car truck, a strut extending from the brake beam and brake heads coupled to the brake beam proximate to right hand and left hand ends thereof. Each brake head holds a brake shoe configured to engage a wheel of the railway car truck. Paddles extend exterior of the brake heads. The paddles have distal ends received in corresponding guide brackets of the side frames to guide movement of the brake beam. Paddle caps cover the distal ends of the paddles. The paddle caps are configured to be received in brake beam wear liners in corresponding side frames of the railway car truck. The paddle caps have a lower coefficient of friction than the paddles.

BACKGROUND OF THE INVENTION

The subject matter herein relates to a railway car truck and, moreparticularly, to a brake beam assembly tor a railway car truck.

In a railway car truck, two axles are held in a pair of laterally spacedside frames, with a bolster extending laterally between and supported oneach side frame. The wheels are press fit on the axles, with the ends ofthe axles also fitted with a roller bearing assembly. The roller bearingassembly is fit into a bearing adapter that is fit into a pedestal jawopening at the longitudinal end of each side frame. Each railway cartruck also includes a braking system having two brake beams that act totransmit braking force through brake shoes to the outer tread of therailway wheels. The brake beams are attached to the side frames incorresponding guide brackets having wear liners therein. For example,paddles extending from ends of the brake beams are received in the wearliners and are movable therein during application of the braking system.Typically, wear plates are positioned within the guide brackets toeliminate wear on the guide brackets.

During operation, the wear plates deteriorate over time. For example,the friction between the paddles and the wear liners eventually causethe wear plates to need replacement. Replacement of the wear linersrequires the railway car truck to be taken off line and disassembled.The paddles are typically made from a hard material, such as a caststeel that wears over time against the wear plates. To protect thepaddles, the paddles are typically flame hardened to prevent wear on thepaddles. Such process adds to the overall cost of manufacture of thebrake beam assembly and to the overall manufacture time of the brakebeam assembly. Additionally, over time the paddles themselves may needreplacement.

A need exists for an improved railway car truck that can reduce thefriction and wear between the brake beam assembly and the wear linersheld by the side frames.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a brake beam assembly for a railway car truck isprovided that includes a brake beam configured to be mounted betweenopposed side frames of the railway car truck, a strut extending from thebrake beam and brake heads coupled to the brake beam proximate to righthand and left hand ends thereof. Each brake head holds a brake shoeconfigured to engage a wheel of the railway car truck. Paddles extendexterior of the brake heads. The paddles have distal ends received incorresponding guide brackets of the side frames to guide movement of thebrake beam. Paddle caps cover the distal ends of the paddles. The paddlecaps are configured to be received in brake beam wear liners incorresponding side frames of the railway car truck. The paddle caps havea lower coefficient of friction than the paddles.

In another embodiment, a railway car truck is provided having a bolsterhaving laterally opposite ends and two side frames transverse to thebolster and supporting the opposite ends of the bolster. Each side framehas a guide bracket on an inner side of the side frame. Brake beam wearliners are received in corresponding guide brackets on the side frames.The brake beam wear liners each have a pocket. A brake beam assembly issupported on the bolster and side frames. The brake beam assemblyincludes a brake beam mounted between the side frames, a strut extendingfrom the brake beam and brake heads coupled to the brake beam. Eachbrake head holds a brake shoe configured to engage a wheel of therailway car truck. Paddles are provided at opposite ends of the brakebeam assembly. The paddles are received in corresponding guide bracketsto guide movement of the brake beam. Paddle caps cover the paddles andare received in pockets of corresponding wear liners. The paddle capshave a lower coefficient of friction than the paddles.

Optionally, the paddle caps reduce the friction and wear on the brakebeam wear liner as compared to the paddles wearing on the brake beamwear liners. The paddle caps may surround the paddles to ensure that thepaddles do not engage the brake beam wear liners. The paddle caps may bemanufactured from a material having a substantially similar coefficientof friction as the brake beam wear liner. The paddle caps may bemanufactured from the same material as the brake beam wear liner.

Optionally, each paddle cap may include a top, a bottom, and a distalend. Each brake beam wear liner may include an upper surface, a lowersurface and a base defining the corresponding pocket. The paddle cap maybe received in the brake beam wear liner such that the top faces theupper surface, the bottom faces the lower surface and the distal endfaces the base.

Optionally, each paddle cap may have a cavity that receives a distal endof the corresponding paddle. The paddle caps may be held on the paddlesby an interference fit. Each paddle cap may include rounded edges andcorners facing the brake beam wear liner. An exterior surface of eachpaddle cap may engage the corresponding brake beam wear liner to guidemovement of the paddles. The paddle caps may take up a portion of a gapbetween the paddle and the brake beam wear liner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a railway car truck formed in accordance withan exemplary embodiment;

FIG. 2 is a top view of the railway car truck shown in FIG. 1;

FIG. 3 is a perspective view of the railway car truck shown in FIG. 1;

FIG. 4 is a side view of a portion of the railway car truck;

FIG. 5 is a top, partial sectional view of a portion of the railway cartruck;

FIG. 6 illustrates a portion of the brake beam assembly showing a paddlecap poised for loading onto a corresponding paddle of the brake beamassembly.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1-3, a railway car truck 10 is shown. The railwaycar truck 10 includes two laterally spaced side frames 12 and 14,between which a bolster 16 extends. Each of the side frames 12, 14 andbolster 16 are usually a cast steel unitary structure. Various internalribs and supports lend strength, along with a savings in overall weightfor each of such cast steel truck components.

Axles 20 and 22 extend laterally between the side frames 12, 14. Railwaywheels 24 are press fit on the ends of the axles 20, 22. Roller bearingassemblies 26 are also provided on the ends of the axles 20, 22. Theside frames 12, 14 include side frame openings 28 aligned with thebolster 16.

The bolster 16 includes bolster ends 32 and 34, which extend through theside frame openings 28. Spring groups 36 support the bolster ends 32 ona side frame lower support 42. The side frames 12, 14 include verticalcolumns 44 that are longitudinally spaced and form the side frameopenings 28 therebetween. The lower support section 42 has variousraised structures adapted to position the spring group 36 thereupon.

The side frames 12, 14 include laterally spaced pedestal jaws 46 whichare the further most lateral extent of the side frames 12, 14. Eachpedestal jaw 46 forms a pedestal jaw opening 48, which is defined by aroof section 50, an outer wall 52, and an inner wall 54. The pedestaljaw opening 48 is adapted to receive a bearing adapter 56 therein. Thebearing adaptors 56 rest on the roller bearing assemblies 26.

The railway car truck 10 includes a brake system 60 having brake heads62 that support brake shoes 64. The brake system 60 is operated to pressthe brake shoes 64 against the railway wheels 24. The brake heads 62 maybe fabricated or cast steel devices. The brake system 60 is supportedfrom the side frames 12, 14 and the bolster 16 and is illustrated withadditional reference to FIG. 4.

The bolster 16 includes on its upper surface a bolster center plate 66,which includes a bolster center plate wear liner 68. Also included onthe upper surface of the bolster 16 is a pair of laterally spaced sidebearings 70.

FIG. 4 is a side view of a portion of the railway car truck 10illustrating a portion of an inner side 80 of the side frame 14. Theside frame 14 includes guide brackets 82 extending inward from the sideframe 14. Optionally, the guide brackets 82 are integrally formed withthe side frame 14. The guide brackets 82 are positioned along thevertical column 44 proximate to the side frame opening 28. The guidebrackets 82 are positioned proximate to the lower support section 42 oneach side of the side frame opening 28. Similarly, the side frame 12(shown in FIGS. 2 and 3) includes a pair of guide brackets that aresubstantially similar to the guide brackets 82.

Each guide bracket 82 includes a pocket 84 that is surrounded by anupper wall 86 and a lower wall 88. The upper and lower walls 86, 88 aresubstantially parallel to one another and project from the side frame 14to define the pocket 84. In an exemplary embodiment, the guide bracket82 has an open side furthest from the side frame 14 that provides accessto the pocket 84. The open side extends between the upper and lowerwalls 86, 88. The pocket 84 receives a brake beam wear liner 90 whichreceives a portion of the brake system 60 (shown in FIG. 3). Forexample, the brake beam wear liners 90 receive paddles 120 and paddlecaps 122 of the brake system 60 as described in further detail below. Inan exemplary embodiment, the guide brackets 82 may conform to AARstandard S-366. The AAR standards call for the guide bracket 82 to beinclined to the horizontal at an angle of 14° for 40, 50, 70, and 90-100ton cars, and at an angle of 16° for 125 ton cars.

The brake beam wear liners 90 each include a pocket 92 defined by anupper surface 94, a lower surface 96 and a base 98 at the interior ofthe pocket 92. The brake beam wear liners 90 protect wear on the guidebrackets 82. The break beam wear liners 90 are replaceable once worn,such as by removing the break beam wear liners 90 from the guidebrackets 82 and inserting new break beam wear liners 90 therein.However, the railway car truck 10 must be taken out of service for suchrepair. Reducing wear on the break beam wear liners 90 reduces thefrequency of replacement allowing longer service life for the railwaycar truck 10.

In an exemplary embodiment, each brake beam wear liner 90 ismanufactured from a metal material, such as a cast steel material. Othertypes of metal materials may be used in alternative embodiments. A metalmaterial used for the brake beam wear liner 90 may be manufactured by aprocess other than casting, such as stamping and forming the brake beamwear liner 90. Alternatively, the brake beam wear liner 90 may befabricated from a synthetic material, such as a nylon material, a highmolecular weight polyethylene material, and the like. Optionally, impactresistant synthetic materials may be used. Other types of syntheticmaterials may be used in alternative embodiments. The break beam wearliner 90 may be manufactured from a material selected to provide certaincharacteristics, such as reduced friction or wear characteristics ascompared to the material of the guide bracket 82.

FIG. 5 is a top, partial sectional view of a portion of the railway cartruck 10 illustrating brake beam wear liners 90 received incorresponding guide brackets 82 of the side frames 12, 14. FIG. 5 alsoillustrates a portion of the bolster 16, the railway wheels 24 and aportion of the brake system 60. The brake system 60 includes brake beamassemblies 100 each including a brake beam 102, a strut 104, and brakeheads 62 coupled to ends of the brake beam 102 and strut 104.

The brake beam 102 is generally elongated between a right hand end 106and a left hand end 108. The brake beam 102 extends laterally betweenthe side frames 12, 14. The brake shoes 64 are coupled to the brakeheads 62, which are provided proximate to the ends 106, 108 of the brakebeam 102, generally aligned with the railway wheels 24.

The strut 104 includes a right hand end 110 and a left hand end 112. Inan exemplary embodiment, the strut 104 is separate and discrete from thebrake beam 102 and is coupled to the brake beam 102 with the ends 110,112 proximate to the ends 106, 108, respectively. Alternatively, thestrut 104 may be integral with the brake beam 102, such as formed aspart of a common casting process. The strut 104 extends at acute anglesfrom the brake beam 102 to an apex at a center portion. A standoffsection 114 extends from a center portion of the brake beam 102 to theapex of the strut 104.

The brake beam 102, strut 104 and standoff section 114 are typicallycomprised of structural steel, and may be in the form of a hollowstructural steel sections. One or more levers 116 are connected to thebrake beam assembly 100, such as to the standoff sections 114, toactuate the brake beam assembly 100 during braking.

The brake beam wear liners 90 are shown loaded into the guide brackets82. Ends of the brake beam assembly 100 are configured to extend intothe brake beam wear liners 90. For example, the paddles 120 and paddlecaps 122 (shown in greater detail in FIG. 6) may be provided at theopposite ends of the brake beam assembly 100 to extend into the brakebeam wear liners 90. The paddles 120 are extensions at the end of thebrake beam assembly 100. The paddles 120 may be integrally formed withthe brake beam 102, the strut 104 and/or the brake heads 62. In otheralternative embodiments, the paddles 120 may be separate and discretefrom the other components of the brake beam assembly 100. For example,the paddles 120 may be coupled, such as fastened, to the brake beam 102,the strut 104 and/or the corresponding brake head 62. The paddle caps122 are coupled to the paddles 120 to reduce friction and wear betweenthe brake beam assembly 100 and the brackets 82 during use of the brakesystem 60.

FIG. 6 illustrates a portion of the brake beam assembly 100 showing oneend thereof illustrating one of the paddle caps 122 poised for loadingonto the corresponding paddle 120. The paddle 120 includes a distal end124. The paddle 120 includes a top 126 and a bottom 128. The paddle 120includes first and second edges 130, 132, which may define a front and arear of the paddle 120.

The paddle cap 122 is sized and shaped to cover at least the end of thepaddle 120. The paddle cap 122 provides a sacrificial layer over thepaddle 120. The paddle cap 122 includes a cavity 134 that receives thepaddle 120. The cavity 134 is defined by an interior surface 136 thatengages the exterior of the paddle 120 when coupled thereto. Optionally,the paddle cap 122 may be held on the paddle 120 by an interference fit.Alternatively, the paddle cap 122 may be secured by other means orprocesses, including bonding, welding, using fasteners, using latches,or other means.

The paddle cap 122 includes a top 138, a bottom 140, a distal end 142and first and second edges 144, 146. The first and second edges 144, 146may define a front and a rear of the paddle cap 122. In an exemplaryembodiment, the paddle cap 122 may have rounded edges and corners at theintersections of the top 138, bottom 140, distal end 142 and first andsecond edges 144, 146. The rounded edges may reduce damage to the brakebeam wear liner 90 when moving therein. The rounded edges may reduce thechance of lockup with the brake beam wear liner 90 when moving therein.

The paddle cap 122 may be manufactured from a material having a lowcoefficient of friction. The paddle cap 122 may be manufactured from amaterial having a lower coefficient of friction than the paddle 120. Thepaddle cap 122 may be manufactured from a material that is less abrasivethan the paddle 120. The paddle cap 122 may be manufactured from amaterial having a coefficient of friction that is less than half thecoefficient of friction of the paddle 120. Optionally, the paddle cap122 may be manufactured from the same or a similar material as the brakebeam wear liner 90 (shown in FIG. 5). In an exemplary embodiment, thepaddle cap 122 may be manufactured from a polymer material, such as asynthetic material, a nylon material, a high molecular weightpolyethylene material, and the like. The paddle cap 122 may be molded ormay be manufactured by other processes.

Returning to FIG. 5, during operation of the brake system 60, the brakebeam assemblies 100 may be pressed toward the corresponding railwaywheels 24 to apply braking pressure to the railway wheels 24. The levers116 actuate the brake assemblies 100 during braking. Movements of thebrake beam assemblies 100 are guided by the brake beam wear liners 90.For example, the brake beam wear liners 90 limit movement of the brakebeams 102 along a generally linear path toward, and away from, therailway wheels 24. The brake beams 102 have a linear range of motiondefined by the brake beam wear liners 90.

The brake beam assemblies 100 are not physically connected to the sideframes 12, 14, Rather, the brake beam assemblies 100 are free-floatingbetween the side frames 12, 14. The brake beam assemblies 100 have anaxial length measured between the distal ends 142 of the paddle caps122. The axial length of each brake beam assembly 100 is selected to fitbetween the brake beam wear liners 90. The brake beam wear liners 90associated with a particular brake beam assembly 100 are spaced apartfrom one another by a lateral distance that is longer than the axiallength of the brake beam assembly 100. As such and with the lowcoefficient of friction and round edges of paddle caps 122, binding ofthe brake beam assembly 100 is reduced or eliminated.

During operation of the brake system 60, the brake beam assemblies 100are actuated between retracted positions and advanced positions. In theretracted position, the brake beams 102 are positioned closer to thebolster 16. In the advanced position, the brake beams 102 are actuatedaway from the bolster 16, thus pushing the brake shoes 64 toward thecorresponding railway wheels 24 to apply braking pressure to the railwaywheels 24. The levers 116 actuate the brake assemblies 100 duringbraking. Movement of the brake beam assemblies 100 is guided by thebrake beam wear liners 90. For example, the brake beam wear liners 90limit movement of the paddles 120 and paddle caps 122, and this thebrake beams 102, along a generally linear path toward, and away from,the railway wheels 24 between the advanced and retracted positions. Thebrake beams 102 have a linear range of motion defined by the brake beamwear liners 90.

During operation of the brake system 60, the paddle caps 122 reduce thefriction between the brake beam assembly 100 and the brackets 82. Morebraking force can be applied to the wheels 24 as opposed to using aportion of such force to overcome the forces to move the brake beamassembly 100 from the retracted position to the advanced position. Ascompared to conventional systems without paddle caps, the paddle caps122 protect the paddies 120 and reduce wear on the paddles 120 and onthe brake beam wear liners 90. For example, conventional brake systemsput the paddle in direct contact with the brake beam wear liner 90 andthe hardened, rough surface of the paddle increases wear on the brakebeam wear liner 90. The steel-polymer (or steel-steel) sliding surfacebetween conventional brake systems and the brake beam wear liner 90 hasa high coefficient of friction and thus increased resistance to brakingaction, which can create more stress and wear on the brake beam wearliner 90. Increased resistance may reduce the braking efficiency and mayreduce the service life of the brake pads due to heavy drag.

The brake system 60, with the paddles caps 122, provides apolymer-polymer (or polymer-steel) sliding surface between the brakebeam assembly 100 and the brake beam wear liner 90, which reducesfriction and wear. Reduced wear over time on the components of therailway car truck 10 increases the service life of the railway car truck10. The reduction in friction reduces drag when the brakes are released,which may increase the service life of the brake pads 64. Additionally,providing the paddle caps 122 may reduce a cost of manufacture of thebrake beam assembly 100 by eliminating the need to flame harden thepaddles 120, as is typical of conventional brake beam assemblies toprevent wear of the paddies of such assemblies. Flame hardening is aprocess that adds expense to the manufacture of the paddles 120, andeliminating the need for such process may reduce the overall cost ofmanufacturing the paddles 120 and/or the brake beam 102.

The paddle caps 122 may take up portions of gaps that would otherwiseexist between the paddles 120 and the brake beam wear liners 90. Forexample, portions of gaps between the paddles 120 and the bases 98 ofthe brake beam wear liners 90. By partially filling such gaps, thepaddle caps 122 may help center or align the brake beam assembly 100between the side frames 12, 14 and prevent binding of either end of thepaddles 120 with the brake beam wear liners 90. For example, the brakebeam assembly 100 may move freely and squarely between advancedpositions and retracted positions as the brake beam assembly 100 isactuated and released, and apply braking force evenly on both brakeshoes 64. Holding the brake beam assembly 100 in position may furtherprevent the railway wheels 24 from tilting causing premature wear of thewheels 24 and rail tracks. The radiused or curved ends of the paddlecaps 122 may reduce friction and/or damage between the paddle caps 122and the brake beam wear liners 90. Having the distal ends 142 of thepaddle caps 122 parallel to the base 98 may reduce friction and/ordamage between the paddle caps 122 and the brake beam wear liners 90,for example by ensuring a surface as opposed to an edge engages thebrake beam wear liners 90.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventionwithout departing from its scope. Dimensions, types of materials,orientations of the various components, and the number and positions ofthe various components described herein are intended to defineparameters of certain embodiments, and are by no means limiting and aremerely exemplary embodiments. Many other embodiments and modificationswithin the spirit and scope of the claims will be apparent to those ofskill in the art upon reviewing the above description. The scope of theinvention should, therefore, be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled. In the appended claims, the terms “including” and“in which” are used as the plain-English equivalents of the respectiveterms “comprising” and “wherein.” Moreover, in the following claims, theterms “first,” “second,” and “third,” etc. are used merely as labels,and are not intended to impose numerical requirements on their objects.Further, the limitations of the following claims are not written inmeans—plus-function format and are not intended to be interpreted basedon 35 U.S.C. §112, sixth paragraph, unless and until such claimlimitations expressly use the phrase “means for” followed by a statementof function void of further structure.

1. A railway car truck comprising: a bolster having laterally oppositeends; two side frames transverse to the bolster and supporting theopposite ends of the bolster, each side frame having a guide bracket onan inner side of the side frame; brake beam wear liners manufacturedfrom a synthetic material chosen from a nylon, or a high molecularweight polytheylene received in corresponding guide brackets on the sideframes, the brake beam wear liner having a pocket; a brake beam assemblysupported on the holster and side frames, the brake beam assemblycomprising: a brake beam mounted between the side frames; a strutextending from the brake beam; brake heads coupled to the brake beam,each brake head holding a brake shoe configured to engage a wheel of therailway car truck; paddles at opposite ends of the brake beam assembly,the paddles being received in corresponding guide brackets to guidemovement of the brake beams; and paddle caps covering the paddles, thepaddle caps being received in pockets of corresponding wear liners, thepaddle caps having a lower coefficient of friction than the paddles:,wherein the paddle caps are manufactured from a material having asubstantially similar coefficient of friction as the brake beam wearliner.
 2. The railway car truck of claim 1, wherein the paddle capsreduce wear on the brake beam wear liner.
 3. (canceled)
 4. The railwaycar truck of claim 1, wherein the paddle caps are manufactured from thesame material as the brake beam wear liner.
 5. The railway car truck ofclaim 1, wherein each paddle cap has a cavity that receives a distal endof the corresponding paddle.
 6. The railway car truck of claim 1,wherein each paddle cap includes a top, a bottom, and a. distal end, andwherein each brake beam wear liner includes an upper surface, a lowersurface and a base defining the corresponding pocket, the paddle capbeing received in the brake beam wear liner such that the top faces theupper surface, the bottom faces the lower surface and the distal endfaces the base.
 7. The railway car truck of claim I. wherein each paddlecap includes rounded edges and corners facing the brake beam wear liner.8. The railway car truck of claim 1, wherein the paddle caps surroundthe paddles to ensure that the paddies do not engage the brake beam wearliners.
 9. The railway car truck of claim 1, wherein an exterior surfaceof each paddle cap engages the corresponding brake beam wear liner toguide movement of the paddles.
 10. The railway car truck of claim 1,wherein the paddle caps are held on the paddles by an interference fit.11. The railway car truck of claim 1, wherein the paddle caps take up aportion of a gap between the paddle and the brake beam wear liner.
 12. Abrake beam assembly for a railway car truck, the brake beam assemblycomprising: a brake beam configured to be mounted between opposed sideframes of the railway car truck, the brake beam having opposite righthand and left hand ends; a strut extending from the brake beam; brakeheads coupled to the brake beam proximate to the right hand and lefthand ends thereof, each brake head holding a brake shoe configured toengage a wheel of the railway car truck; paddles exterior of the brakeheads, the paddles having distal ends configured to be received incorresponding guide brackets of the side frames to guide movement of thebrake beam with respect to the side frames; and paddle caps covering thedistal ends of the paddles, the paddle caps being configured to bereceived in brake beam wear liners comprised of a nylon or a highmolecular weight polyethylene material in corresponding side frames ofthe railway car truck, the paddle caps having a lower coefficient offriction than the paddles, wherein the paddle can are manufactured froma nylon or a high molecular weight polyethylene material.
 13. The brakebeam assembly of claim 12, wherein the paddle caps reduce wear on thebrake beam wear liner.
 14. (canceled)
 15. The brake beam assembly ofclaim 12, wherein each paddle cap has a cavity that receives a distalend of the corresponding paddle.
 16. The brake beam assembly of claim12, wherein the paddle caps surround the paddles to ensure that thepaddles do not engage the brake beam wear liners.
 17. The brake beamassembly of claim 12, wherein each paddle cap includes a top, a bottom,and a distal end, the top, bottom and distal ends being configured toface corresponding surfaces of the brake beam wear liners.
 18. The brakebeam assembly of claim 12, wherein each paddle cap includes roundededges and corners facing the brake beam wear liner.
 19. The brake beamassembly of claim 12, wherein an exterior surface of each paddle cap isconfigured to engage a corresponding brake beam wear liner to guidemovement of the paddles.
 20. The brake beam assembly of claim 12,wherein the paddle caps are held on the paddles by an interference fit.